Sailing World magazine's National Offshore One-Design Regattas want to catch new sponsors for the U.S.' largest sailing race series, following IBM Corp.'s departure after three years as sole sponsor. Slated for May through September, the ninth annual event involves 950 boats and 10,000 participants. Title sponsorship is $350,000; supporting sponsorships cost $25,000. The New York Times Co.'s Sailing Co., New York, coordinates. Contact: (212) 789-3066.

Atlantic City (N.J.) Holiday Classic, in honor of basketball legend John B. McLendon Jr., is seeking sponsors for its second annual tournament slated for Dec. 14 to 16. The event features eight men's teams and four women's teams, culminating in championships, with local TV coverage. Sponsorship packages range from $40,000 to $125,000 with on-site and pre-event promotion. DB Enterprises, Philadelphia, coordinates. Contact: (215) 843-1118.

International Robot Games, slated for June 22 and 23 in Pomona, Calif., is putting together sponsorships for the first annual competition, held in conjunction with a computer expo. Sponsorships for the games, expected to draw 10,000 people, offer on-site exposure and product promotion backed by multimedia publicity. Costs range between $75,000 and $150,000. Skycastle Entertainment, Burbank, coordinates. Contact: (213) 851-3618.

Coast to Coast Karaoke Challenge is lining up sponsors for its third annual competition scheduled for February through August, involving an estimated 100,000 participants in 400 cities. Co-sponsored by Pioneer New Media Technologies, the event seeks sponsors on various levels at costs ranging from $5,000 to $40,000. Apple Entertainment, Seattle, coordinates. Contact: (800) 700-4695.

Team Vortex, a civilian jet demonstration team, is taking off with sponsors for the 1996 season, offering corporate representation on its two F-35 Draken jets. Sponsorships also include on-ground promotions at air shows and other events at costs beginning at $35,000. AYS Sports Marketing, Margate, N.J., coordinates. Contact: (609) 822-7825.

1996 Men's Marathon U.S. Olympic Trials, slated for Feb. 16 and 17 in Charlotte, N.C., are teaming up with sponsors. A total of 125 athletes will compete for three spots on the U.S. Olympic men's marathon team. The event includes a range of other races under presenting sponsor NationsBank; lower-level sponsorships range between $2,500 to $30,000. Muhleman Marketing, Charlotte, N.C., coordinates. Contact: (704) 568-2520.